There isn't one single name for the process used by white blood cells to fight infection. It's a complex process with several stages and involves many different types of white blood cells. Here's a breakdown of some of the key terms:

1. Immune Response: This is the general term for the body's defense against infection.

2. Phagocytosis: This is the process by which certain white blood cells (neutrophils and macrophages) engulf and destroy pathogens (bacteria, viruses, etc.).

3. Inflammation: This is a localized response to infection characterized by redness, swelling, heat, and pain. It involves the release of chemicals that attract white blood cells to the site of infection.

4. Antibody Production: B lymphocytes (B cells) produce antibodies that bind to specific antigens (molecules on pathogens) and help neutralize them.

5. Cell-mediated Immunity: T lymphocytes (T cells) directly attack infected cells and help regulate the immune response.

6. Complement System: A group of proteins that work together to lyse (destroy) pathogens and enhance inflammation.

Therefore, the "name" for the process used by white blood cells to fight infection depends on the specific stage or mechanism you're interested in. The immune system is a complex and multifaceted network, and all of these processes work together to protect the body from infection.